Registration with federal police on VITEM IV student visa

It's almost been 24 days since I entered brazil and I haven't registered with the federal police yet.
My period of stay is from 30/10/17 to 6/12/17 which is approximately 37 days and my visa is valid for 60 days.

I'm currently living in a small town and the federal police station here doesn't do the said work.. I'll have to travel to a far away city and the process to register seems a bit tedious and lengthy.
Is it absolutely necessary to register with the federal police station even if I'm leaving the country in less than 40 days of my arrival?
Is there any alternative method to this process? Like pay a fine at the airport when I'm leaving the country or something?
What happens if I'm unable to register within 30 days of my arrival in Brazil?

Nothing will probably happen. you might ask the federal police where you are that you tried to register with them. When you leave if you are questioned just show them the letter. I wouldn`t worry about it. also, don`t volunteer anything about it.

Jim

My doubt arised after checking websites which said any foreigner with a visa different than student is needed to register with the federal police but at the same time I read somewhere that registration is needed when stay extends 90 days. So all this is a bit confusing.